Noise is constant and loud sound. To measure the loudness, or volume of sounds, people use a unit called a decibel. When a sound is louder than 70 decibels, it can cause noise pollution. Do you know that the noise from a vacuum cleaner or a motorcycle can result in permanent hearing loss after eight hours? The sounds of a concert are even more serious. They can reach as high as 130 decibels and may cause immediate and permanent hearing loss. Noise pollution can also lead to headaches and high blood pressure. If you are listening to music through headphones, and other people can hear it, it means the music is too loud and unsafe. If there seems to be a ringing or buzzing in your ears, it means the noise is affecting you and damaging your hearing. Wearing earplugs when you go to concerts or other loud events, and listening to music through headphones or headsets at safe levels can help you reduce the effects of noise pollution. 1. When does noise pollution happen? .............................................................................................................................................. 2. Is the noise from a vacuum cleaner or a motorcycle more serious than the noise of a concert? .............................................................................................................................................. 3. Does noise pollution cause headaches and high blood pressure? ............................................ 4. What should we do reduce the effects of noise pollution when we listen to music through headphones or headsets?......................................................................................................... ..............................................................................................................................................